There are a lot of ways you could do this. Personally I take a piece of
wood wide enough to make 2 of these with and cut round holes, using
either a hole saw in the drill press or a wing cutter. You could rip the
board in half to yield 2 pieces.


I built a simple wine rack beneath a bar a few years ago that resembles one
of the racks in the photo and this approach is similar to the way I did it.

For the back rack that holds the bottle base, I used a hole saw slightly
larger that the "average" bottle of wine. I actually allowed the saw to saw
"air" at the top of the hole and then trimmed the rack back to just below
the centerline of the cutouts.

I did pretty much the same at the front with a smaller hole saw, then cut
away the edge as above. I did arrange them so the bottles were in a slight
'neck up' position that still kept the cork wet. Then, I ran over the edges
with a 1/4" cove bit to dress them up a bit. I'll email a photo to you
separately.